The preparation of morpholine from diethylene glycol and ammonia is not new, but all of the known prior processes for the manufacture of morpholine from diethyleneglycol and ammonia require the use of large amounts of hydrogen or ammonia, which results in the use of high pressure equipment and the employment of stringent operating conditions.
For instance, in U.S. Pat. No. 3,155,657, there is described a process for the preparation of morpholine from diethylene glycol, anhydrous ammonia and hydrogen at pressures up to 500 atmospheres and temperatures up to 240.degree. C. using a catalyst of about 0.2 to 5 percent by weight of ruthenium on alumina.
In U.S. Pat. No. 3,151,112, there is described a process for the preparation of morpholine from diethylene glycol and anhydrous ammonia and hydrogen at temperatures of 150.degree. C. to 400.degree. C. and at pressures between 30 and 400 atmospheres where the partial pressure of the hydrogen is at least 10 atmospheres using catalysts from the group of copper, nickel, chromium, cobalt, magnesium, molybdenum, palladium, platinum, rodium, their oxides or mixtures thereof.
Japanese patent application No. 039937 published as No. 7132189 discloses the preparation of morpholine from diethylene glycol, ammonia and hydrogen at 25 atmospheres using a catalyst prepared by boiling a 50/50 nickel/aluminum alloy in water for 4 hours.
In U.S. Pat. No. 3,347,926 there is disclosed a process for producing aliphatic amines by ammonolysis by reacting a hydroxy containing compound, such as primary and secondary alcohols with ammonia, primary and secondary amines in the presence of Raney nickel catalyst containing some chromium at temperatures from 150.degree. C. to 275.degree. C.
In U.S. Pat. No. 3,709,881 there is disclosed the preparation of N-alkyl morpholines from diethylene glycol and an alkyl, dialkyl or trialkyl amine in the presence of a hydrogenation catalyst preferably in the presence of hydrogen, at elevated temperatures and pressures in the presence of water.
In the Russian Journal, Zh. Vses. Khim. Obshchest, 14 (5); pp. 589-590, Dobrovolski et al disclose the reaction of diethylene glycol/ammonia/hydrogen at mole ratios of 1/10/5 in the gas phase over a nickel based catalyst.
In U.S. Pat. No. 2,412,209 there is disclosed a process for the preparation of aliphatic amines by the condensation of ammonia with dihydric alcohols by saturating the glycol with ammonia in the presence of a hydrogenation catalyst, such as Raney nickel, copper chromite, copper nickel chromite, iron, etc.
Japanese patent application No. 013882 published as 7131863 discloses the preparation of morpholine from diethylene glycol and a gaseous mixture of ammonia and hydrogen and steam at about 8 moles of hydrogen per mole of ethylene glycol at about 190.degree. C. and using a nickel catalyst.
Japanese patent application No. 103791 published as No. 7241908 discloses the preparation of morpholine by reacting ethylene glycol with ammonia and hydrogen utilizing a catalyst which is a mixture of nickel, copper and molybdenum oxide.
Japanese patent application No. 039936 published as No. 7132188 discloses the preparation of morpholine by reacting ethylene glycol, ammonia in the presence of hydrogen at about 26 atmospheres at 240.degree. C. utilizing a Raney nickel alloy.
The present invention has the advantage over these prior processes in that no hydrogen whatever is required in the process of this invention. Therefore, the use of the high pressure of the prior art is eliminated. Also, one of the advantages of the process of this invention is that the ammonia can be utilized in the form of ammonium hydroxide.
The present invention has other advantages over these prior art processes in that it employs temperatures and pressures much lower than the prior art methods. The invention also provides greater selectivity to morpholine than the prior art methods. The catalyst which is employed in the present invention is much easier to regenerate in a continuous reactor than in the prior art batch methods.